As far as I can see several people are saying they get visitors who did not show, but I am not sure if this effects total visits as well as flags as I have no other counter on the site. I know I have had visits from Germany several times over the weekend, but no flag. You can see the counter itself at http://www.resurgam.info/MissingPortraits/Home/aboutthissite.html

The domain for my site, www.MissingPortraits.info, is on a redirect from UK2.net and I can check the last 1,000 lines of code passing thro there, so here are 7 flags that do not show (I have only included 1 hit from each country, and not included those with only an IP address as the source):
spider17.yandex.ru - - [03/Jan/2011:03:44:10 +0000] "GET /robots.txt HTTP/1.1" 404 - "-" "Mozilla/5.0 (compatible; YandexBot/3.0; +http://yandex.com/bots)"

xdsl-188-154-89-19.adslplus.ch - - [09/Jan/2011:15:34:20 +0000] "GET / HTTP/1.1" 200 761 "-" "Mozilla/5.0 (Windows; U; Windows NT 6.1; en-GB; rv:1.9.2.13) Gecko/20101203 Firefox/3.6.13 GTB7.1 ( .NET CLR 3.5.30729; .NET4.0C)"

p4fcb25da.dip0.t-ipconnect.de - - [05/Jan/2011:15:33:32 +0000] "GET / HTTP/1.1" 200 760 "-" "Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10_6_5; de-de) AppleWebKit/533.19.4 (KHTML, like Gecko) Version/5.0.3 Safari/533.19.4"

121-84-179-136f1.osk3.eonet.ne.jp - - [06/Jan/2011:07:13:47 +0000] "GET / HTTP/1.1" 200 760 "-" "Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10_6_5; en-us) AppleWebKit/533.19.4 (KHTML, like Gecko) Version/5.0.3 Safari/533.19.4"

s5146de2a.adsl.wanadoo.nl - - [05/Jan/2011:08:25:40 +0000] "GET / HTTP/1.1" 200 760 "http://www.reuniontalk.com/showthread.php?p=27950" "Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10_6_5; nl-nl) AppleWebKit/533.19.4 (KHTML, like Gecko) Version/5.0.3 Safari/533.19.4"

8.32-181-91.adsl-dyn.isp.belgacom.be - - [06/Jan/2011:20:56:55 +0000] "GET / HTTP/1.1" 200 760 "-" "Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; WOW64; Trident/4.0; GTB6.6; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0)"

86-42-195-159-dynamic.b-ras1.cld.dublin.eircom.net - - [07/Jan/2011:21:14:35 +0000] "GET / HTTP/1.1" 200 760 "http://www.facebook.com/l.php?u=http%3A%2F%2Fwww.missingportraits.info%2F&h=9342a" "Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; WOW64; Trident/4.0; GTB6.5; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; InfoPath.2)"

In addition, http://s06.flagcounter.com/countries/jRH/ shows France only for last October when the site was only half built, but
ip-193.net-82-216-227.roubaix.rev.numericable.fr - - [04/Jan/2011:22:29:36 +0000] "GET / HTTP/1.1" 200 760 "-" "Mozilla/5.0 (Macintosh; U; PPC Mac OS X 10_4_11; fr) AppleWebKit/533.19.4 (KHTML, like Gecko) Version/4.1.3 Safari/533.19.4"

Perhaps someone can clarify this for me.

Cheers, Colin

PS - so many Macs out there!